The present invention relates generally to techniques in which a flexible structure is attached to a support surface. More particularly, the invention relates to techniques in which a variable volume is defined between a flexible structure and a support surface.
Techniques have been previously proposed in which a flexible material such as polymer is deposited on a substrate. For example, Doany, F. E., and Narayan, C., “Laser release process to obtain freestanding multilayer metal-polyimide circuits,” IBM J. Res. Develop., Volume 41, No. 1-2, January/March 1997, pp. 151-157, describe deposition of polymer films with metal wiring features, after which the structure is removed from the substrate by a laser separation process that ablates a polymeric layer, forming a freestanding structure. Bakir, M. S., Reed, H. A., Mulé, A. V., Jayachandran, J. P., Kohl, P. A., Martin, K. P., Gaylord, T. K., and Meindl, J. D., “Chip-to-Module Interconnections Using ‘Sea of Leads’ Technology,” MRS Bulletin, January 2003, pp. 61-63 and 66-67, describe application and patterning of a sacrificial polymer on a wafer, followed by deposition of an overcoat polymer; the sacrificial polymer is then thermally decomposed to form an air gap embedded within the overcoat polymer, after which vias are fabricated to expose die pads and allow electrical connection of leads on the overcoat polymer to a chip in the wafer.
Previous techniques, however, are limited in the variety of articles that can be produced with a flexible structure attached to a support surface. It would be advantageous to have additional techniques for flexible structures attached to support surfaces.